1. Technical Field
This invention relates to a theft deterrent system of a computing apparatus. More specifically, a method and apparatus are provided for changing the responsiveness of a theft deterrent function in relation to power consumption of the computing apparatus.
2. Description of the Prior Art
As technology advances, there is a strong desire for making electronic items smaller and more portable. Laptop computers are portable personal computers that can be easily carried from one location to another location. There is a need to secure laptop computers from theft as well as use by an unauthorized person, and to provide a theft deterrent system to mitigate access by an unauthorized person.
Japanese Patent Publication 2004-240744 to Tomoyuki discloses a monitoring device for movement of an item of interest. As disclosed, the '744 publication teaches a monitoring mode switched to an ON position in response to a relative location of the item of interest being moved. If the relative location of the item returns to a predetermined value, the monitoring mode is switched to a suspend mode. The '744 provides for one of two positions for monitoring an item, an ON position and a suspend position. Each of these positions is set in response to movement of a designated item of interest. However, there is no support for adjusting sensitivity of the monitoring mode after it has been switched to an ON position.
Japanese Patent Publication 2003-109127 to Yuukou et al. discloses a system for generating an alarm in response to theft of a portable article. There are two communication modules in the '127 alarm system. A first communication module is loaded on the portable article, and a second communication module is loaded on an article of a person. The first and second communication modules communicate through transmission of high frequency radio signals. While a high frequency signal is transmitted and received between the two communication modules and a burglar prevention mode is set to ON, a warning alarm remains silent. However, at such time as the portable article and the article of the person are separated beyond a tolerated distance and the high frequency signals between the two communication modules is not received, an alarm is generated. Accordingly, the '127 publication requires generation of high frequency signals at all times between the two communication modules when the alarm system is set and does not provide for adjustment of the frequency setting of the signals between the two communication modules.
Japanese Patent Publication 2002-092752 to Tokusho provides a device for a wireless theft detector of an object through a vibration sensor. A transmitting unit is provided to transmit a control signal to a receiving unit. An alarm is generated when it receives a signal from the vibration sensor or when it does not receive a communication from the transmitting unit. However, as in the '744 publication to Tomoyuki, there is no support in the '752 publication for adjusting the sensitivity of the control signal.
Each of the prior art publications discussed above utilize wireless communication between an item being monitored and a remote unit. In the each of these systems there is a constant transmission of radio signals between two units at a set frequency. Transmission of radio signals requires electricity. If the item being monitored has a battery supply, there is only a limited amount of electricity available for a limited amount of time. Most laptop computers come with batteries that deliver power to the computer when it is not otherwise receiving power from an alternative source. However, batteries have a limited amount of power, and when the power expires the battery requires recharging. There is no support or suggestion for enabling the communication of the radio signals between the two entities to be adjusted to compensate for a limited energy source. Accordingly, there is a need for a wireless system that monitors theft and/or vibration of a portable item while conserving energy and thereby extending the operable period of time.